News Release

Mayo Clinic study finds apathy and depression predict progression from mild cognitive impairment

Next, researchers will study whether treating neuropsychiatric symptoms in MCI can delay the onset of dementia

Peer-Reviewed Publication

Mayo Clinic

ROCHESTER, Minn. -- A new Mayo Clinic study found that apathy and depression significantly predict an individual's progression from mild cognitive impairment (MCI), a disorder of the brain that affects nerve cells involved in thinking abilities, to dementia, including Alzheimer's disease and Lewy body dementia. The study was presented at the International Conference on Alzheimer's Disease in Honolulu on July 11, 2010.

"An important area of study is the identification of biomarkers and clinical predictors for the progression from normal cognition to mild cognitive impairment and mild cognitive impairment to dementia," says Yonas E. Geda, M.D., a Mayo Clinic neuropsychiatrist and the study's lead investigator. "We knew from previous smaller studies that neuropsychiatric symptoms like depression, apathy and agitation seem to predict progression from mild cognitive impairment to dementia, so we set out to look at this hypothesis in a population-based setting with a larger sample size."

Depression and apathy are neuropsychiatric symptoms that are often difficult to distinguish, according to Dr. Geda. Depression causes changes in mood, thinking, physical well-being and behavior, while apathy is loss of motivation without associated feelings of being depressed or blue.

As part of the Mayo Clinic Study of Aging, Dr. Geda and a team of Mayo Clinic researchers identified 358 individuals with mild cognitive impairment and used a questionnaire to collect data on depression and apathy. Then, they prospectively followed individuals to the outcome of dementia (a median of 2.8 years). Among 87 individuals with depression, 30 (34.5 percent) developed dementia. Of the 271 individuals without depression, 59 (21.8 percent) developed dementia. Among 60 individuals with apathy, 22 (36.7 percent) developed dementia. Of the 298 individuals without apathy, 67 (22.5 percent) developed dementia.

After adjusting for age, gender and education, the researchers found that the individuals with mild cognitive impairment and depression had a 66 percent increased risk of developing dementia than those individuals with mild cognitive impairment without depression. Likewise, the individuals with mild cognitive impairment and apathy had a 99 percent increased risk of developing dementia than those individuals with mild cognitive impairment without apathy.

"These findings highlight the importance of thoroughly evaluating newly-diagnosed patients with mild cognitive impairment for neuropsychiatric symptoms. The next step is to conduct a study to find out if treatment of depression or apathy in MCI may delay the onset of dementia," says Dr. Geda. "This delay could have a huge impact on the quality of life for individual patients and their families, not to mention the broad public health implications of delaying the societal and economic burden of dementia. In fact, a previous biostatistics study from our colleagues at Johns Hopkins indicated that delaying dementia by a mere one year could reduce the prevalence of Alzheimer's disease by nearly 800,000 million fewer cases in 2050."

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Other members of the Mayo Clinic research teams included Rosebud Roberts, M.B., Ch.B; David Knopman, M.D.; Teresa Christianson; V. Shane Pankratz, Ph.D.; Bradley Boeve, M.D.; Walter Rocca, M.D.; Robert Ivnik, Ph.D.; Eric Tangalos, M.D.; and Ronald Petersen, M.D., Ph.D.

About Mayo Clinic

For more than 100 years, millions of people from all walks of life have found answers at Mayo Clinic. These patients tell us they leave Mayo Clinic with peace of mind knowing they received care from the world's leading experts. Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. At Mayo Clinic, a team of specialists is assembled to take the time to listen, understand and care for patients' health issues and concerns. These teams draw from more than 3,700 physicians and scientists and 50,100 allied staff that work at Mayo Clinic's campuses in Minnesota, Florida, and Arizona; and community-based providers in more than 70 locations in southern Minnesota, western Wisconsin and northeast Iowa. These locations treat more than half a million people each year. To best serve patients, Mayo Clinic works with many insurance companies, does not require a physician referral in most cases and is an in-network provider for millions of people. To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. For information about research and education, visit www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource for your general health information.


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